Leer



L,A J. HARTLE LEER , 1926 3 Sheets-Sheet Filed Dec. lO

Patented Sept. 9, 1,930

PATENT oFFlc LOUIS J. HARTLE, O1? PITTSBURGH, PENN SYLVNIA.

LEER y Application filed December 10, 1926. Serial No. 153,844.

This invention relates to furnaces and more particularly to tunnel'type furnaces such, for example, as the leers commonly 'employed for annealing glass articles.

An object of this invention is to provide a leer of such construction and arrangement as to permit the utilization of heat which has hitherto been permitted to escape.

A fur-ther object is to provide a leer of the type set forth capable of more efficient operi ation than is possible with similar devices now in use and known to me.

A still further object is to provide a leer of such construction and arrangement that the temperature of any predetermlned seotions can be controlled independently of any other section.

A stil further object is to provide a device of the t pe set forth of such arrangement that it can be installed directly on a factory floor without the necessity of' any substructure, and is thus capable of being dismantled and moved from one location to' another at a nominal cost.

These and other objects which will be apparent to those skilled in this particular art are accomplished by means of the present invention, one embodiment of which is illustrated in the accompanying drawings, in which Figure 1 is "a vertical longitudinal sectional view of a leer constructed in accordance with one form of--this invention. Fig. 2 is a view of the structure illustrated in Fig. 1, showing the same half in plan and half in horizontal section on the line 2-2 of Fig. 4. Fig. 3 is a transverse section on the line 3 3 ofFig. 1, taken through the firebox. Fig. 4 is a similar view on the line 4-4 of Fig. l and Figs. 5 and `6 are similar views on the lines 5 5 and 6-6, respectively, of Fig. l. I

The particular embodiment of" the present invention which has been chosen for the purposes of illustration is shown as applied to a tunnel type lee` such as commonly employed in annealing glass articles and includes a frebox or combustion chamber where suitable fuel is burned and from which the .t0 products of combustion are lead through iues arranged both above and below the tunnel for the purpose of heating the latter in their travel toward an associated stack. The present invention contemplates controlling the flow of heating fluid through both the upper and lower iues in such a way as to enable the obtaining o'f any desired temperature gradient from one end of the tunnel to the other. In the resent embodiment of thisl invention this 1s accomplished by providing one flue with a plurality of outlet por-ts spaced at suitable intervals longitudinally thereof and connecting these outlet ports with the associated stack. By this means the amount of heating iuid in this particular flue can be reduced during its fiow therethrough in kany desired manner, as gra-dually or as suddenly as desired. In order to provide an additional control of the temperature gradient in the tunnel, and also to inrease the efficiency of this type of leer, the present invention provides a mechanism for reclaiming a part or all of the heat remaining in the iiuid which has passed through the lues and into the stack, and returning such fluid to la heating fiue so that heat which would otherwise be lost is thereby utilized. y

The particular embodiment of the present invention which has been chosen for the purposes of illustration includes a fireboX or combustion chamber 10 having an opening 11 through which a burner 12 projects a suitable flame, and the interior of the firebox is provided with a baffle 13 which is 'so positioned as to evenly distribute the heating Huid throughout the chamber. F lues or passages 14 connect the firebox with tunnel heating lues 15 which extend longitudinally along the roof ofthe tunnel.' These heating iues are preferably formed of cast iron sections which include a bottom plate 16 forming the roof of the usual tunnel 17 and provi ed with a number of vertical ribs 18, integral therewith and running longitudinally of the tunnel in such a manner that when a number of these sections arelassociated in end to end relation a plurality vof -heating flues 15 are formed along the top of the tunnel, the tops of which iues are formed by suitable plates 19-secured to the vertical ribs in any desired manner.

The lirebox is also connected by downwardly extending Hues or passages 2O with auxiliary fireboxes 22 communicating with the bottom heating flues 23 which extend longitudinally beneath the tunnel and which are preferably constructed of cast iron sections similar to the sections over the roof of the tunnel. As shown in Fig. 6 the lower heating ilues lead to a common chamber or header 24 which is' connected, by vertically extending passages 25 and horizontal passages 26 provided with dampers 27, to the usual stack 28. The lues 14 which connect the firebox with the upper heating flues are adapted to be controlled by suitable dampers 29 and the flues 20 leading from the lirebox to the lower auxiliary ireboxes 22 are adapted to be opened andclosed by suitable dampers 30. A y

Outlet ports 31 are positioned at predetermined points longitudinally of the upper heating flues 15 and are connected to the stack by a suitable outlet flue or pipe 32. Each port is opened or closed by a damper 33.

A blower 34, driven by a motor 35 or any otherdesired device is adapted to withdraw heating gases yfrom the stack through an opening 36 and pipe 37 which is controlled by a damper 38 and return them to heat exchanging relation with the tunnel. A damper'39 is provided in the stack so as to permit the blower to reclaim any part or all of the gases reaching the stack. In the present embodiment of this invention the blower forces the heating fluid withdrawn from the stack with different points in the lower heating iues by means of a plurality of downwardly extending pi es 41, each of which communicates with a orizontal flue or header 42'extending across the bottom of the leer. Each header 42 is connected with inlet ports 43 leading to the bottom heating iues 23 and dampers 44 control the opening and closing of such ports,

In operation the burner 12 projects a flame through the associated openlng 11 into Ithe firebox or combustion chamber 10 where it strikes the baiiie and spreads throughout the entire chamber so as to completely fill the same. Suitable air inletopenings 45, see Fig. 3, are associated with the combustion chamber so as to supply atmospheric air thereto and dampers 46 are assoclated with these openings. From thecombustion cham` ber the heating gases How through passages suitable regulation with the various 14 to the upper heating flues 15 and through passages 20 to the auxiliary fireboxes 22 and thence to the lower heating ues 23. By dampers 33 which control the opening and closing of the outlet ports spaced long gitudinally along the upper heating flue 15 the heating effect of into a header or'pipe 40 which is connected' the gases flowing therethrough can be accuf rately and Vdelicately adjusted. The speed of the heating gases flowing through the lower heating lues will be controlled by the position of the dampers 27, positioned 1n the outlet fines leading from the lower heatlng lues to the stack. By returning the desired amount of heating fluid from the stack to the lower flue 23 a large amount of heat which would otherwise be lost is reclaimed so that the most efficient heating of the leer is 0btained. The amount of heating gases reclaimed may be varied by suitably adjusting the draft damper 39 in the stack and the damper 38 in the liue connecting the stack with the blower 34. The point or points of the lower flue to which the reclaimed heating gases are returned can be determined and varied by adjusting the dampers44 associated with each inlet 43 leading from the pipe 40 to the lower flues.

Itwill be apparent that the proper regulation of all dampers will produce the desired temperature gradients in the portions of the tunnel adjacent to the top and bottom heating flues, thus making it possible to obtain a substantially uniform temperature in every transverse section or zone of the tunnel. The character of the temperature curves obtained by plotting the temperatures in the tunnel as ordinates and the distances along the tunnel as abscissas is determined by the character of similarly plotted curves for both the bottom and top iues, and these are controlled by the location and adjustment of the dampers in the ports communicating with these iues. It will be apparent that the resulting temperature gradients may be controlled at will and that the point or zonek of maximum drop in temperature may be shifted longitudinally of the tunnel to the place desired. For example, the more reclaimed heat that is permitted to enter through a given port of the bottom flue the quicker will be the rise in temperature at that point and this reclaimed heat can be induced at any of the point-s at which it is desired to raise the tunnel temperature. Obviously the more heat reclaimed the less fuel it will be necessary to chamber up to a and desire to secure by Letters Patent is:

1. A leer having in combination a tunnel, flucs in close heat-exchanging relation therewith for the passage of heating fluid and thereinlwithout departing communicatin means for repassing at least a ortion of such Huid through at least a part o said Hues.

2. A leer having in combination a tunnel, Hues in close heat-exchanging relation therewith for the passage of heating Huid and means for returnin at least a part of such Huid to said Hues a er it emerges therefrom.

3. A leer having in combination a tunnel, a Hue in close heat-exchanging relation therewith for the passage of heating Huid and 'means for causing such Huid which has passed through said Hue to be returned thereto.

- 4. A leer having in combination a tunnel, a Hue in close heat-exchanging relation therewith for the passage of heating Huid, a stack communicating with said Hue 'and means for diverting'heating Huid from said stack and returning it to said Hue for the purpose of controlling temperatures therein.

5. A leer having in combination a tunnel, a Hue in close heat-exchanging relation therewith for the passage of heating Huid, a stack with' said Hue, a blower adapted to dlvert heating Huid from said stack and a pipe for returning such Huid to said fluea 6. A leer having in combination a tunnel, a Hue in close heat-exchanging relation therewith for the passage of heating Huid, a stack communicating with said Hue, a blower adapted to divert heating Huid from said stack, a pipe for returning such Huid to said Hue and connections between said pipe and diH'erent points of said Hue whereby said Huid can be returned thereto at any of said points.

7. A leer having in combination a tunnel, heating Hues in close heat-exchanging relation therewith including a Hue beneath the bottom of said tunnel and means for returning at least a part of the heating Huid which lhas passed through saidHue to said bottom Hue.

. 8. A leer havin in combination a tunnel, heating Hues in c ose heat-exchanging relation therewith including a Hue beneath the Hoor thereof, means for returning at least a part of the heating Huid passing through, said Hues to said bottom Hue and connections for permitting such Huid to enter said Hue at a predetermined point longitudinally thereof.

9. A leer having in combination a tunnel, a Hue in close heat-exchanging relation therewith, means for supplying said Hue with a heating Huid, a plurality of ports spaced longitudinally of said Hue and means for returning heating Huid which has passed through said Hue to one or more of said ports.

10. A leer having in combination al tunnel,

'a plurality of heating Hues in close heat-exchanging relation therewith arranged for the conveyance of heating Huid through said Hues in the same direction and means for returning the Huid to said Hues after it has emerged therefrom.

11. A leer having in combination a tunnel, heating Hues located above and below said tunnel and means for transferring heating Huid from a Hue above said tunnel to one below said tunnel.

12. A leer having in combination a tunnel, a plurality of Hues in heat-exchan ing relation therewith, including Hues a ove and below said tunnel, means for regulating the passage of heating Huid in sfaced longituinal portions of said Hues or controlling the temperature in said tunnel, and means for transferring the heating Huid to portions of the lower Hue after said Huid has emerged from said upper and lower Hues.

In testimony whereof, I have hereunto subscribed my name this 2nd day of December,

LOUIS J. HARTLE. 

